2

I have an ASP.NET Core 8.0 Web API that is deployed in k8s.

What is happening is that after some time (random might range from 30 minutes to a day or more), the following exception is printed in console and application terminates i.e. k8s restarts it.

Unhandled exception in Main: System.NullReferenceException: Object reference not set to an instance of an object.

at System.Collections.Concurrent.ConcurrentDictionary`2.Enumerator.MoveNext()
at System.Net.Http.HttpConnectionPoolManager.RemoveStalePools()
at System.Net.Http.HttpConnectionPoolManager.<>c.<.ctor>b__11_0(Object s)
at System.Threading.TimerQueueTimer.Fire(Boolean isThreadPool)
at System.Threading.TimerQueue.FireNextTimers()

Also there are some exception related to Kestrel:

System.AggregateException: A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread. (Object reference not set to an instance of an object.)

System.NullReferenceException: Object reference not set to an instance of an object.

at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.ConnectionManager.RemoveConnection(Int64 id)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.TransportConnectionManager.RemoveConnection(Int64 id)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.KestrelConnection`1.ExecuteAsync()
--- End of inner exception stack trace ---

I have made sure that all async are being awaited, all IDisposable are in using blocks.

Improve this question
5
  • Many versions ago I had something similar where I changed Task to Task<bool> and returned true, then when calling: var b = await MyMethodAsync(); I think it made it work, but I never figured out what it was Commented Aug 15 at 10:25
  • I guess there is some Task that is not awaited and is throwing exception. I would look for that. Or try to subscribe to event TaskScheduler.UnobservedTaskException Commented Aug 15 at 11:23
  • @MichałTurczyn above exception later one System.AggregateException: A Task's exception(s) were not observed either by .. is being logged in TaskScheduler.UnobservedException and also set as observed. Also I have gone through all the web api routes from starting of server to crash to make sure that all tasks are awaited. Commented Aug 15 at 11:49
  • You should analyze whatever stack traces you can get. They should point you to the right place in your code. Commented Aug 15 at 11:53
  • @MichałTurczyn The posted stack trace points to Microsoft code. Commented Aug 15 at 15:41
Related questions
432
ASP.NET Core Web API exception handling
241
Return file in ASP.Net Core Web API
683
How do you create a custom AuthorizeAttribute in ASP.NET Core?
Load 7 more related questions Show fewer related questions

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.